JPH07195598A - Thermoplastic resin molded body and its manufacture - Google Patents

Abstract

PURPOSE:To provide superior heat insulation properties and strength for a molded body by integrating a plate-shaped molded body composed of a volume reduced product obtained by reducing the volume of crushed products of a thermoplastic resin foam with a board composed of crushed products of thermoplastic resin foam. CONSTITUTION:The given quantity of volume product, detained by crushing a thermoplastic resin foamed body and heat reducing its volume, is fed into a female mold and uniformized therein, and a male mold is overlapped in a manner of pressing the whole of the upper face of the volume reduced product, and then pressurized. In this way, the plate-shaped molded body 5 is melted successively starting from the volume reduced products on sites in contact with respective molds to form a resin layer by the arrangement, and as for a section close to the center, a number of cavities with hollow inside are formed among respective particles in the state of being fusion bonded or bonded one another. Crushed particles formed by crushing thermoplastic resin foamed body are filled in a mold and a bonding agent applied, and then dried to form a board 6 of crushed product. Then, for instance, in the case of integrating with the bonding agent, the bonding agent is applied on one face of the plate-shaped body 5 or the crushed-product board 6, and then both are overlapped and integrated by fixing by pressure by means of a press.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded product of a volume-reduced product of a thermoplastic resin foam which can utilize a waste product of a foam made of a thermoplastic resin such as expanded polystyrene and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a method of reusing foamed resin moldings such as the above-mentioned polystyrene foam, melt pelletization is carried out and used as a raw material for injection molding, used as a soil improving material, or used as fuel for boilers or the like. It is known to be used as. Further, it has been proposed that after the melt pelletization, the regenerated resin particles are impregnated with a foaming agent to prepare regenerated pre-expanded particles, which are filled in a foam molding die and heat-molded. (For example, Japanese Patent Publication Sho 56
-34171 publication etc.)

[0003]

However, in the above conventional utilization method, when melt pelletization is performed and used as a raw material for injection molding, a large cost is generated in the melt pelletization, and in addition, since it is heated and melted again, This leads to deterioration of the physical properties of the resin, and when it is used as a soil conditioner or fuel, its added value is very small. For these reasons, there is little advantage in recycling the thermoplastic resin foam, and there is a problem in that promotion of recycling is suppressed.

The present invention has been made in view of the above, and an object thereof is to provide a method for effectively reusing a foamed resin molded article such as expanded polystyrene.

[0005]

In order to solve the above problems, the thermoplastic resin molded article according to claim 1 of the present invention is
It is characterized in that a plate-shaped molded body made of a reduced volume product of a crushed product of a thermoplastic resin foam and a crushed product board made of a crushed product of a thermoplastic resin foam are integrated.

According to a second aspect of the present invention, there is provided a method for producing a thermoplastic resin molded article, which comprises a plate-shaped molded article obtained by press-molding a volume-reduced product obtained by reducing the volume of a pulverized product of a thermoplastic resin foam. It is characterized in that a crushed product board obtained by integrating crushed products of a thermoplastic resin foam with an adhesive or the like is integrated with an adhesive or a heating means. As the thermoplastic resin foam, polystyrene foam, polyethylene foam, polypropylene foam, polyester foam, a mixture thereof, a copolymer foam, or the like can be used.

The volume density of the volume-reduced product obtained by reducing the volume of the pulverized product of the thermoplastic resin foam is preferably 0.1 g / cc or more. When it is less than 0.1 g / cc, the strength of the plate-shaped molded product obtained by press molding may not be sufficient.

[0008]

According to the above-mentioned structure of the present invention, a plate-shaped molded product made of a volume-reduced product obtained by reducing the volume of a crushed product of a thermoplastic resin foam has a relatively high density and excellent strength, while the heat A crushed product board made of a crushed product of a plastic resin foam has a relatively small density, is excellent in heat insulating properties, and is lightweight, and thus can be suitably used as a lightweight lightweight heat insulating material having rigidity. Then, the added value to the reuse of the thermoplastic resin foam can be increased.

According to the above-mentioned method, the plate-shaped molded product obtained by press-molding the volume-reduced product obtained by reducing the volume of the crushed product of the thermoplastic resin foam, and the thermoplastic resin foam If the crushed product board in which the crushed product is integrated with an adhesive or the like is the same type of resin, it can be easily integrally molded by heating means or the like. In addition, a plate-shaped molded product obtained by press-molding a crushed product board in which crushed thermoplastic resin foam is integrated with an adhesive or the like, and a volume-reduced product obtained by reducing the crushed thermoplastic resin foam It can be easily sandwiched between them to form a sandwich structure. Therefore, it can be suitably used as a heat insulating material and the like, and the added value can be increased.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following will describe one embodiment of the present invention with reference to FIGS. A plate-shaped molded product made of a volume-reduced product obtained by reducing the volume of a crushed thermoplastic resin foam is used as a thermoplastic resin foam, and foamed with an apparent density of 0.017 g / cc by bead foam molding used as a packaging material for home appliances. A volume-reduced polystyrene molded product was used as a raw material.
The volume-reduced product was crushed by a volume-reducing machine for foamed resin molding FM-25 (manufactured by Sekisui Plastics Co., Ltd.) and heated to reduce the volume. As the expanded polystyrene molded product, burrs or defective products which are unavoidably by-produced in the process of molding the extruded foamed sheet can be used.

The volume-reduced product has a bulk density of 0.3 g / c.
The particle size of the volume-reduced product was about 20 mm at the maximum. Next, a method for manufacturing the above plate-shaped molded body will be described. First, as shown in FIG. 2, the volume-reduced product 1 obtained as described above is put into a female mold 2.
Then, a predetermined amount was charged to obtain a substantially uniform thickness, and subsequently, male molds 3 were superposed so as to press the entire upper surface of the volume-reduced product, and then pressure was applied by a plunger 4 of a press machine. In addition,
The contact surface of each of the molds 2 and 3 with the volume-reduced product 1 is mirror-finished.

At this time, the heating temperature of each of the molds 2 and 3 is set to 190 ° C. at which the volume-reduced product 1 can be melted, the heating time is 5 minutes, and the pressing pressure by the plunger 4 is 3. At 5 Kg / cm2, the volume-reduced product 1 charged into the female mold 2 is compressed to a thickness of 1 / 2.5 and press-molded, then taken out from the female mold 2 and formed into a substantially rectangular plate shape. A molded body 5 was obtained.

The surface of the plate-shaped molded body 5 has the respective dies 2.3.
Since it is easy to sequentially melt inward from the part in contact with, the volume-reduced product 1 in the part in contact with each mold 2 and 3 is sequentially melted and solidified to a thickness of about 5 mm as shown in FIG. The resin layer 5a is formed and the surface 5b of the resin layer 5a is formed.
Was smooth. The plate-shaped molded product 5 obtained as described above has a bulk density of 0.6 g / cc and is lightweight, and the volume-reduced product 1 hardly melts in the portion closer to the center than the resin layers 5a. In the state where the particles were fused or bonded to each other, a large number of millet-like hollow portions 5c having a space inside were formed between the particles.

The above-mentioned plate-like molded body 5 has a hollow portion 5
A resin layer 5a that has a light weight and has sufficient strength due to the resin layer 5a that has been melted and solidified, and has excellent heat insulation due to the hollow portion 5c, and that its surface 5b is smooth and has excellent appearance and dimensions. Has become. In the above example, the one having a cavity inside the plate-shaped molded article is disclosed, but it is not particularly limited, and the whole may be almost resinified, and can be changed according to the required strength. .

As the crushed product board made of the crushed product of the thermoplastic resin foam, the same crushed product as that used in the production of the plate-shaped molded product was used. Next, a method for manufacturing the crushed product board will be described. The crushed product was filled in a mold (not shown), coated with an epoxy adhesive, and then dried to manufacture a crushed product board 6. As the adhesive, a urethane-based adhesive can be used in addition to the epoxy-based adhesive.

Next, a method of integrating the plate-shaped molded product and the crushed product board will be described. First, in the case of integrating with an adhesive, an epoxy adhesive is applied to one surface of the plate-shaped molded body or the crushed product board, and then both are superposed and pressed by a press to be integrated. In this case, a urethane adhesive may be used. Next, in the case of using a heating means to integrate the two, the surface of the crushed product board is previously set to 200
It is melted on the heating plate 7 at about ℃. The heating time at this time was about 10 seconds, and the pressure of the hot plate was about 1 kg / cm @ 2. The surface of the heat plate is preferably treated with Teflon coating or the like in order to improve the peeling of the resin.

After the heating plate was opened, the plate-shaped molded body was quickly placed on the heating surface of the crushed product board and pressed by the plunger 4 at room temperature to integrate the two. The pressing pressure at this time was about 1 kg / cm @ 2, and the pressing time was about 5 seconds. The crushed product board was integrally molded on the opposite surface of the plate-shaped molded product by the same method. The integrally molded thermoplastic resin molded body 8 had a length of 300 mm, a width of 300 mm, and a thickness of 50 mm.

In the above examples, the volume-reduced product 1 has a bulk density of 0.3 g / cc, but the volume-reduced product 1 is not limited to the above-mentioned bulk density, and the thermoplastic resin to be used is not limited thereto. The volume density of the volume-reduced product obtained by reducing the volume of the pulverized product of the thermoplastic resin foam is 0.1 g, though it can be changed depending on the strength required for the foam and the thermoplastic resin molded body 8 to be obtained.
/ Cc or more is desirable. This is 0.1 g /
If it is less than cc, it is lightweight and bulky, so that workability such as handling during press molding may be poor, or the strength of the plate-shaped molded product obtained by press molding may not be sufficient. The volume density of the volume-reduced product 1 is the true density of the thermoplastic resin used, for example, 1.0 for expanded polystyrene.
It does not exceed 5 g / cc.

Further, in the above-mentioned embodiment, an example in which expanded polystyrene is used as the thermoplastic resin foam is given, but the invention is not particularly limited to this, and for example expanded polyethylene, expanded polypropylene, expanded polyester, It is possible to use a mixture of the above foamed resins, or a thermoplastic resin foam (bulk density of 0.001 to 0.19 g / cc) such as a copolymer.

Further, the bulk density of the volume-reduced product 1, its particle size,
Alternatively, by adjusting the heating temperature and the heating time, it is possible to obtain thermoplastic resin moldings having various strengths, heat insulation properties and densities.

[0021]

As described above, the thermoplastic resin molded article according to claim 1 of the present invention comprises a plate-shaped molded article comprising a volume-reduced product obtained by reducing the volume of a pulverized product of the thermoplastic resin foam, and a thermoplastic resin. The crushed product board made of a crushed product of the resin foam is integrated. Therefore, it has excellent heat insulating properties, is lightweight, and has sufficient strength, and thus can be effectively used as a heat insulating material such as a building material.

Further, by using a waste material such as expanded polystyrene molding which is a thermoplastic resin foam for the volume-reduced product, it is possible to further promote the effective use of the recovered material of the thermoplastic resin foam. Play. Further, not only a large added value can be obtained at a low cost, but also the cost of disposing the collected product of expanded polystyrene as an industrial waste can be omitted.

The method for producing a thermoplastic resin molded article according to claim 2 of the present invention is a plate obtained by press-molding a volume-reduced product obtained by reducing the volume of a crushed product of a thermoplastic resin foam as described above. The method is characterized in that a crushed product and a crushed product board in which a crushed product of a thermoplastic resin foam is integrated with an adhesive or the like are integrated with an adhesive or a heating means. Therefore,
Since the thermoplastic resin molded body can be manufactured by a very simple method such as an adhesive or a heating means, it is possible to promote the reuse of the thermoplastic resin foam.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a thermoplastic resin molding according to an embodiment of the present invention.

FIG. 2 is a process drawing showing a part of the process of the method for manufacturing a plate-shaped molded product in one example of the present invention.

FIG. 3 is a cross-sectional view of a main part of a plate-shaped molded body according to an embodiment of the present invention.

FIG. 4 is a process drawing that follows the process of the above manufacturing method,
(A) shows the manufacturing process which heats the surface of a crushed product board, (b) shows the manufacturing process which integrally shape | molds a plate-shaped molded object and a crushed product board.

[Explanation of symbols]

 1 Volume-reduced product 2 Female mold 3 Male mold 4 Plunger 5 Plate-shaped molded product 6 Crushed product board 7 Heating plate 8 Thermoplastic resin molded product

Claims (2)

[Claims] 1. A plate-shaped molded product made of a reduced volume product of a crushed product of a thermoplastic resin foam and a crushed product board made of a crushed product of a thermoplastic resin foam are integrally formed. A thermoplastic resin molded body. 2. A plate-shaped molded product obtained by press-molding a volume-reduced product obtained by reducing the volume of a crushed product of a thermoplastic resin foam and a crushed product of the thermoplastic resin foam are integrated by an adhesive or the like. A method for producing a thermoplastic resin molded article, characterized in that the crushed product board is integrated with an adhesive or a heating means.